- Date: 15th century
- 1 : being such in essence or effect though not formally recognized or admitted <a virtual dictator>
- 2 : of, relating to, or using virtual memory
- 3 : of, relating to, or being a hypothetical particle whose existence is inferred from indirect evidence <virtual photons>
- 4 : being on or simulated on a computer or computer network <print or virtual books> <a virtual keyboard>: as a : occurring or existing primarily online <a virtual library> <virtual shopping>
- b : of, relating to, or existing within a virtual reality <a virtual world> <a virtual tour>
Virtual reality (VR) is a computer-simulated environment, whether that environment is a simulation of the real world or an imaginary world. Most current virtual reality environments are primarily visual experiences, displayed either on a computer screen or through special or stereoscopic displays, but some simulations include additional sensory information, such as sound through speakers or headphones. Some advanced, haptic systems now include tactile information, generally known as force feedback, in medical and gaming applications. Users can interact with a virtual environment or a virtual artifact (VA) either through the use of standard input devices such as a keyboard and mouse, or through multimodal devices such as a wired glove, the Polhemus boom arm, and omnidirectional treadmill. The simulated environment can be similar to the real world, for example, simulations for pilot or combat training, or it can differ significantly from reality, as in VR games. In practice, it is currently very difficult to create a high-fidelity virtual reality experience, due largely to technical limitations on processing power, image resolution and communication bandwidth. However, those limitations are expected to eventually be overcome as processor, imaging and data communication technologies become more powerful and cost-effective over time.